Backfiling Strategy at Gag Island, PT Gag Nickel, Subsidiary of PT ANTAM (Persero) Tbk

PT Gag Nikel is subsidiary of PT ANTAM (Persero) Tbk, doing feasibility study at moment. The purpose of scheduling backfill is to do volume balance between out-pit and in-pit dumping and control amount low grade that goes to stockpile and calculate distances hauled during mining process. The material scheduled divided into overburden, low grade, and ore. The material could be sent to following destinations, overburden to in-pit and out-pit dumps, low grade to in-pit, out-put dumps, stockpiles, and ore to stockpiles only. In controlling dumping sequence, there are three consideration constraints: geotechnical, capacity, and haul distance. Geotechnical constraints use dump slope which ensures maximum dump overall slope angle not exceed 13 -15 degree, also offset dump to face, assist specified distance (50 m) between toe of working face and “toe” of dumps. This di stance must sufficient to allow operation such ore loading and water handling safely and efficiently. Second constraint is capacity that control amount low grade sent to stockpiles. Haul distance as third constraint is way to dump close to current mining o peration. By managing low grade material, when processing technology adequate, those material can be extracted. This shows Antam's good will of resource conservation that conform with sustainability.